Sunday, May 10, 2009

Understanding (Zombie) Conceivability Arguments: Part II

So far we have established that a legitimate conceivability-possibility inference must start from the ideal conceivability of a semantically neutral statement. The final requirement I want to discuss is that the statement to be conceived should be specified in transparent, uncontested terms.What do I mean by a 'transparent' specification? I mean to exclude broad general terms (like 'physical' or 'non-physical') whose extensions might be controversial. This helps us to avoid pointless terminological debates. Note that it's a bit sloppy to argue, "Conceivably a world could be physically just like ours but lack consciousness, therefore physicalism is false," because it is unclear exactly what we are meant to be conceiving: the phrase 'physically just like ours' is too opaque: different people might take it to mean different things. [Plus, its invocation of actuality - 'our world' - technically violates the semantic neutrality requirement.] So, for maximum rigor, it should be replaced by a precise microphysical description P that - without making any explicit reference to qualia - is accepted by the physicalist as true of our world. We can then argue from the conceivability of (P & ~Q) to the precise conclusion that the qualitative properties in Q are not reducible to the properties specified in P, and so must be explicitly added as further primitives to the base facts.

It is important to note the precise conclusion here. It is not that Q is non-physical, or that physicalism is false. It is merely that Q does not reduce to anything included in P. Importantly, none of the premises say anything about whether P exhausts the physical properties. (We chose P so that the physicalist should agree that it does exhaust the physical properties, but that occurs outside of the scope of the argument itself. This is a vital point that I will return to.) So one could, in principle, respond that Q is a primitive "physical" property that doesn't reduce to any of the other ones listed. This "physicalist" will insist that a full specification of the physical base facts P* must include Q as a basic conjunct, in which case (P* & ~Q) will be straightforwardly inconsistent, seeing as how it would be equivalent to ((P & Q) & ~Q) for some P. Clearly, this "physicalist" is completely immune to refutation by the kind of conceivability argument discussed here.

That's fine, except that this is to be a "physicalist" in name only. Once you grant that qualia are primitive, and must be explicitly included in the base facts, that's all the dualist cares to establish. Whether you call these primitive mental facts "physical" or "non-physical" is mere semantics.

The target of the zombie argument is instead the strict physicalist, who refuses to countenance primitive mental properties. He believes that we can fully specify the base facts of the world without any explicit mention of qualia. P alone will suffice for Q, on his view, just as P suffices to fix the macroscopic table and chair facts. But since P (unlike P*) makes no explicit mention of Q, we have some chance of running a conceivability argument against this view, since it looks like (P & ~Q) could be conceivable. It's not a knock-down argument, of course: one could reasonably deny that it really is ideally conceivable at the end of the day. But at least the zombie argument has a chance, unlike in the previous case.

Why am I harping on about this at such length? Well, I think this background can help us diagnose the misunderstanding implicit in Richard Brown's dismissive parody:

I am conceiving of a world that is just like this one in all non-physical respects except that it lacks consciousness. Therefore dualism is false.

This exhibits the same sloppiness exhibited by the sloppy version of the zombie argument discussed at the very start of this post. The difference is that while the zombie argument can (as demonstrated) be made more precise, this parody -- what RB now calls his "zoombie argument" -- cannot.

What's the problem? Well, as before, it's entirely opaque what we are supposed to be conceiving, since there is no uncontested specification of the "non-physical respects" of the world that we can plug in to the argument. I take it Brown wants to plug in the actual non-physical description 'NP', whatever it may be. But dualists and physicalists have wildly differing ideas about what this description will end up looking like. Physicalists presumably think it will be empty (i.e. tautologous: devoid of information), whereas dualists think it will list all the qualia facts Q. Let's consider these two possibilities in turn.

Suppose NP states nothing (i.e. is tautologous). The argument is then as follows: "It's conceivable that (TAUT & ~Q). Therefore dualism is false." Well, that's clearly invalid. The possibility of ~Q is clearly compatible with dualism!

Suppose NP just states Q. Then the argument is: "It's conceivable that (Q & ~Q). Therefore dualism is false." But in this case the first premise is transparently false.

So, you see, whichever way we fill out the precise details of the parody argument, it very clearly fails (unlike the original zombie argument which, though controversial, can at least get off the ground, since "P & ~Q" is neither trivial nor trivially false).

You might wonder: if the parody is so atrocious, why would anyone have ever been tempted to take it seriously? I think the answer is just that they haven't fully appreciated how restrictive the form of conceivability inference relied upon by the original zombie argument is. If one assumed that the zombie argument must take the sloppy (opaque) form introduced earlier, then one may well be right to see the parody as being of the same form, and hence undermining that form of argument. I'm happy to grant this: opaque conceivability arguments are no damn good. But - once again - this does nothing to impugn the zombie argument, since it can be stated in a more transparent form (as described*).

* = (Of course, I've really only provided a schema of the argument. The real thing will have the placeholder 'P' replaced by a long, transparent description. But insofar as we have a rough grasp of what P will look like, we can draw tentative conclusions about whether the expanded version of 'P & ~Q' is likely to be conceivable.)

The zoombie world is a COMPLETE non-structural/non-functional duplicate of our world. NP is not just some random list of non-physical properties! It is a complete list of the actual non-physical properties. So, if there are no non-physical qualitative properties in NP then the actual qualitative properties that you and I enjoy are not non-physical properties.

I hope it's clear by now that this is a wildly different form of argument from the zombie argument I've given. Instead of using NP as a mere placeholder for some list of non-physical properties (neutrally and transparently specified), he is explicitly building in its status as "a complete list of the actual non-physical properties". So when he asserts that (NP & ~Q) is conceivable, this is mere shorthand for the same old sloppy, opaque conceivability claim as before (viz., that conceivably, "a world could have all the actual non-physical properties but lack qualia"). In effect, he is (unwittingly) pretending to give a precise, transparent specification by mimicking the superficial form of my argument, when in fact the underlying form and actual content of his argument hasn't changed a bit from the sloppy version.

To recap: a legitimate conceivability argument should begin by providing a transparent, uncontested specification of what is to be conceived. The zombie argument does this, by taking whatever specification 'P' the physicalist likes (which the dualist will not contest). The 'zoombie' parody, by contrast, does not meet this condition. This is indicative of further problems downstream -- and indeed, when we consider the two main candidates for fleshing out 'NP' (namely: TAUT or Q), we immediately see that neither has the faintest hope of grounding a conceivability argument against the dualist. The entire force of the parody argument rests on the opacity of 'NP', and -- unlike the real zombie argument -- it cannot survive being rendered transparent.

[This is all just to elucidate the objection originally stated in a couple of sentences in my 'zombie review'.]

It's true that the "type-A" (analytic) physicalist claims that P a priori entails Q. If they're right, then the zombie argument will ultimately fail. But this is a highly non-trivial claim: it isn't obvious that they're right (even some [type-B] physicalists deny it), so this is enough for the conceivability argument to "get off the ground", in my minimal sense. Even if it ultimately fails, at least it will require some serious conceptual analysis for the physicalist to refute.

So I'm not claiming that it ultimately succeeds. I'm just claiming that it's not an obvious failure like the parody argument -- which can be refuted on purely logical grounds, no complex conceptual analysis required.

Hi Richard, thanks for fleshing out your objection in such detail. I am finding this quite helpful!

You say,

"So, for maximum rigor, it should be replaced by a precise microphysical description P that - without making any explicit reference to qualia - is accepted by the physicalist as true of our world. We can then argue from the conceivability of (P & ~Q) to the precise conclusion that the qualitative properties in Q are not reducible to the properties specified in P, and so must be explicitly added as further primitives to the base facts."

This passage just illustrates the problem that I am trying to bring out. If you do have such a P then (P & ~Q) will not be conceivable! The fact that we aren't able to fill in P in the way you require is why it seems to us like we can imagine zombies. Now I grant that if we did fill in P like you want we would then be in a position to determine whether or not physicalism is true (or more precisely whther or not Q is reducibe to P). So there is a possible zombie argument (the one that you could give at the ideal limit) but we are not in a position to give it yet (as you seem to acknowledge). So, the problem with the zombie argument is that no matter how careful the physicalist is you assert that you can conceive of whatever they give you as not entialing qualitative facts. But I can conceive of them entailing those facts! So you haven't got a "uncontested specification of what is to be conceived" since you want it to be conceived that the qualitative facts are not entailed by P, which I can't do); so, though we can agree on what is specified in P we do not agree about what is entailed by P and conceiving that is what is at issueSo, to try and bring out my frustration I give the zoombie argument. I can conceive of a non-physical duplicate lacking non-physical qualitative consciousness. No matter what I learn about non-structural/non-functional properties I just don't see anything that forces us to include qualitative properties. In fact I seem to be able to conceive of all of the non-structural/non-functional facts obtaining without any qualitative properties without any contradiction. But if you know something about non-structural/non-functional properties that suggest that qualitative properties must be included in a complete specification of thse kinds of properties then let me know. But I just can't see what kind of thing you could point to that would do the job.

Perhaps it would be useful for you to tell us a little about non-structural/non-functional properties...what are they like? I don't mean tell me about experiencing pain or seeing red. Tell me what these have in common with numbers and other non-physical entities/properties. Perhaps if we know more about them we will be able to see why a complete list of them must include qualitative properties...(I of course know that you will say that you cannot give a complete list of the non-structural/non-functional properties without explicitly talking about qualitative properties so I am not asking for a reason to think that the non-physical properties must entail that there are qualitative properties, but something else. I mean what is it about these kinds of properties that forces them to be non-physical)

'you haven't got a "uncontested specification of what is to be conceived" since you want it to be conceived that the qualitative facts are not entailed by P'

Not at all. You're conflating the initial specification - how the argument is set up (which is all I require to be uncontested) - with substantive claims about whether the argument succeeds (in particular, whether the specified statement really is ideally conceivable). Any substantive argument will be controversial in the second sense. It's only the first kind of contestation that's immediately disqualifying.

Think of it this way: first we need to state a precise argument, then we can assess it. You complain that it's controversial how to assess the zombie argument. I agree it's controversial but deny that that's ground for complaint. You respond with the zoombie argument to demonstrate the problem. But the problem with the zoombie argument is entirely different: not that it is controversial how to assess it once it is made precise (as I have shown, on any precisification it can immediately be seen to fail). The problem is instead that there isn't any "precise argument" there at all. It's unclear what argument you are even trying to give, let alone how to assess it. And it's the former unclarity -- an unclarity not shared by the zombie argument -- that is disqualifying.

"No matter what I learn about non-structural/non-functional properties I just don't see anything that forces us to include qualitative properties."

This sounds like you are wanting to say that whatever specification 'NP' the dualist offers, in no case will it obviously entail Q. But this isn't so, since the dualist will want to offer a specification that explicitly includes Q. And nothing more obviously entails Q than Q itself.

This creates a stark disanalogy with the (strict) physicalist. For in your case, I really can say that whatever P you might provide, I doubt it'll entail Q. I can say this because, unlike the dualist, you are committed to giving me a specification that makes no explicit mention of Q itself. This makes all the difference.

Finally: your last paragraph is puzzling. I've said time and time again that nothing hangs on whether we call qualia "non-physical". I certainly don't think they share any special commonality with numbers/abstract objects (since I don't really think there are any such things -- or rather, it isn't a meaningful question). My claim is simply that qualia must be included as primitive in the base facts. They are not reducible to any other kind of fact (physical or non-physical). So I don't think looking at other putative non-physical properties would be at all informative. If you want to include qualia as brute among the "physical" properties, that's cool with me: that's just the position of my old friend, the "physicalist in name only".

I don't know if it's fussily precise to say "a priori", since P includes a posteriori facts about the actual world.

The whole "conceivability" argument though, hinges on whether it really is conceivable that P might not entail Q. As you note in part I: Instead, it invokes the technical notion of ideal conceivability, or what can be conceived without (even implicit) contradiction. This stricter sense of conceivability more plausibly entails possibility. (The flip side of this is that it makes the premise [zombies are conceivable] more controversial!) -

Fundamentally the question is a scientific one, not a philosophical one: we must determine whether or not Q really is reducible to P.

"The whole "conceivability" argument though, hinges on whether it really is conceivable that P might not entail Q."

Yes, of course, I did already say this. It's controversial whether the argument ultimately succeeds or not. The purpose of these posts is just to explain why the argument doesn't obviously fail (the way some people, having misunderstood the argument, seem to think).

P.S. In a case like this where what I'm really providing is an argument schema (rather than the fully fleshed-out argument itself), it's important to be very clear about what features are built into the final argument, and what features are merely used 'externally', e.g. in selecting and setting up the final argument. (I might write another post on this distinction, since it's quite interesting.) For example, we rely on scientific inquiry in deciding what 'P' is appropriate to use in the argument. But (for any given P and Q) it's purely a matter of a priori philosophical inquiry whether P entails Q.

[Nit-picky correction: the question whether (P & ~Q) is really conceivable is one major 'hinge' of the argument. But it isn't the whole debate, since many physicalists accept this premise and instead deny that conceivability entails possibility.]

You're conflating the initial specification - how the argument is set up (which is all I require to be uncontested) - with substantive claims about whether the argument succeeds (in particular, whether the specified statement really is ideally conceivable). Ah, I was confusing that in this post! Sorry about that.

You complain that it's controversial how to assess the zombie argument.I was complaining about that, but you seem to agree that it is controversial and so doesn't prove that physicalism is false (it 'gets off the ground' in your terms, and I have all along admitted that zombies are prima facie conceivable so I think we agree about this. My original complaint was against those who think that the zombie argument demonstrates that physicalism is false). But as I have been arguing over at my post the original zombie argument actually does suffers from the same shortcoming. If Q is done neutrally then there is no threat to physicalism (just as if NP is specified neutrally there is no threat to dualism).

This sounds like you are wanting to say that whatever specification 'NP' the dualist offers, in no case will it obviously entail Q. But this isn't so, since the dualist will want to offer a specification that explicitly includes Q. And nothing more obviously entails Q than Q itself.Not quite. What I want to know is what is it about NP that forces us to include qualitative properties in it? In other words what is inconceivable about a complete NP that lacks qualitative properties?

As for the last paragraph, I was trying to bring out, as I think I did, the fact that the way you specify Q will be in such a way as to make the zombie argument a type-(i) contestible argument...

I am sure that this is sloppy and needs to be cleaned up but I have to go to work! I'll check back in this afternoon...

Yes, I agree. That would be a problem if my purpose here were to fully evaluate the argument. But my purpose for now is more just a matter of the initial groundwork -- ensuring everyone understands the argument, and refuting overly-hasty dismissals. (One upshot of this is that I think every reasonable person who understands the issue -- whatever their personal stance -- should be able to agree with everything I'm saying here. I really just take myself to be correcting basic misunderstandings, not asserting anything controversial. Of course, once we get into substantively evaluating whether the zombie argument succeeds, then reasonable controversy may ensue!)

"Brown's parody might charitably be read as applying [only] to those trivial arguments"

This would require us to ignore Brown's ongoing protestations. He thinks his parody undermines the zombie argument, period. So I wrote this post to make absolutely clear why this is not so.

Brown - "controversial and so doesn't prove that physicalism is false"

Huh? For an argument to be controversial is not thereby to fail. It is just to be controversial whether it succeeds in proving what it sets out to prove. Maybe it does, maybe it doesn't; reasonable people can disagree.

"If Q is done neutrally"

Q is just an ordinary description of some actual conscious experience: the colour blue, say. The physicalist has no reason to contest (something like) the following specification: "RC is having a visual experience of blueness." There's nothing especially opaque about the specification, so they can happily accept it for purposes of setting up the argument; they simply think that P will ultimately be shown to entail this Q.

"What I want to know is what is it about NP that forces us to include qualitative properties in it?"

This is a confused question. Like I already said, I don't think there's anything distinctive about the broad category of the non-physical in virtue of which the primitive qualia facts fit there rather than elsewhere. The very fact that you ask this question suggests that you haven't understood my position.

"In other words what is inconceivable about a complete NP that lacks qualitative properties?"

That depends, what is NP? Again, you've missed the whole point of my post. We're talking about schematic arguments whereby capital letters serve as mere placeholders. They should ultimately drop out of the picture entirely, to be replaced by some precise description.

Now, you are effectively asking the question, "Is it conceivable that the precise description will entail thus and so?"

But this is ambiguous between de dicto and de re readings of 'the precise description'.

You are using the de dicto interpretation, which is to run an opaque conceivability argument, and I've already agreed that "opaque conceivability argument are no damn good."

To grasp the zombie argument, you have to instead invoke the de re interpretation of the schema I've given. What's to be conceived is not the statement: "Maybe once we fill out P we'll find that it is compatible with ~Q." Instead, the [future] zombie argument will concern the conceivability of the statement that will be obtained by the following method: replace the 'P' in "P & ~Q" by whatever microphysical account of the world the physicalist ultimately accepts.

I wonder if you think there is any interesting connection between conceiving of zombies and approaching skeptical "other minds" scenarios.

It seems to me that zombies are prima facie conceivable if they do not contradict anything that we know, and they are ideally conceivable if they do not contradict anything that we can possibly know. Since epistemic possibility is indicative, rather than subjunctive possibility, a believer in zombies should conclude that it is an unanswerable question whether or not there are zombies at the actual world.

So a type-a materialist, if they agree that the question of actual zombies can’t be answered a priori, must conclude that we can answer skeptical problems empirically through science. Can we say that categorically?

Well, I'm not much of a philosopher, I'm a neuroscience graduate student, but it seems to me that if physicalism requires that there be empirical neuroscientific answers for skeptical problems of other minds, then it is not likely to be a tenable position. At the very least, this is an idea alien to neuroscientists.

Hi Soluman, that's a nice point, though a little off-topic, so I've moved it to a new post.

P.S. A tangential correction: conceivability concerns what we can't rule out a priori. It's fine to conflict with things we know empirically: as it happens, I know I'm sitting down, but it's coherently conceivable that I be standing up instead. So the conceivability of zombies is compatible with (fallible, not entirely certain) knowledge that there aren't actually any such. We might come to have this justified true belief through induction, say.

Huh? For an argument to be controversial is not thereby to fail.Yeah, sorry about that. What I meant was that you seem to agree that we cannot, as of right now, conclusively say that (P & ~Q) is actually ideally conceivable. My initial complaint was motivated by dualists arguing that zombies were actually ideally conceivable now. I thought that one of your responses to Eliezer suggested that you thought that. But your post zombie review makes it clear that we basically agree about this point. As we approach the ideal limit we will be able to either see that the zombie thought experiment is successful or not. All we can say now is that zombies are prima facie conceivable and then we differ on what our ideal reasoning will look like as we approach the limit. You think we'll head towards see that (P & ~Q) is in fact ideally conceivable while I think we will head towards seeing that (P & ~Q) has an implicit contradiction and so isn't ideally conceivable.

But then I wonder why you object when I say that, as of right now all the current zombie argument can do is to pump your intuitions about where ideal reasoning will end up. That is, the zombie argument, as it stands now, is only good for figuring out where your intuitions lie or correcting an implicit tension in one's "web of beliefs" and so for testing whether you think dualism or physicalism is true. That is, it can't, as of now, be used to demonstrate the falsity of physicalism; do you dispute this? I don't for instance, think that Dave Chalmers agrees with this. I think he thinks that (P & ~Q) is ideally conceivable and that we know this now...

I came up with the zoombie argument to try and show that this was true. The point was supposed to be something like "well, we have two prima facie conceivable scenarios which can't both be ideally conceivable. Furthermore we can't yet tell a priori which is actually contradictory; in fact which seems more likely to be the ideally conceivable one turns on whether one is antecedently disposed to physicalism or dualism." Your specific objection to the form of the zoombie argument doesn't seem to affect this point, does it?

But I do think that the zoombie argument has the same short coming as the original zombie argument, which is what all of the fuss is actually about.

You say, " The physicalist has no reason to contest (something like) the following specification: "RC is having a visual experience of blueness.""

But actually the physicalist does. First a nit-picky point; what we want to know is whether or not RC is having a conscious visual experience of blueness. I hold that there are unconscious visual experiences of blueness and that when such visual experiences are unconsciousness there is nothing that it is like for the person who has the experience. So the specification is "RC is having a conscious visual experience of blueness"

But here is where the problem arises. You want (P & ~Q) to be read de re, right? Now, the de re/de dicto distinction is a dark and obscure distinction but I assume that you mean that we are to replace the placeholders with precise specifications of the properties in question. So 'c-fiber firing' will be replaced with a complete account of the actually discovered neural correlates of pain, and 'activity in V4' will be replaced with the actually discovered neural correlates of color vision and then these will be replaced with complete descriptions in terms of physics (to make things simpler I will stick to the neuroscientific terms). But the physicalist will hold that 'a conscious visual experience of blueness' can be replaced, salve veritate, with its neuroscientific term (this is a consequence of the de re reading; we are talking about the actual properties not the phrase). So in this case (P & ~Q) will amount to (activity in V4 and not activity in V4). This is because the physicalist thinks that (activity in V4=conscious visual experience of blueness) is true. It is this identity that licenses the entailment. So Q is contested: I want to give it the physicalist de re reading and you won't allow it. You have to either give it the de dicto reading (where it is the property 'conscious visual experience of blueness,' but NOT the property that is identical to this property, that gets evaluated) or the de re reading you give to it has to the dualists'...same as my NP.

To Repeat: you cannot let me replace Q with whatever [qualitative] account of the world the physicalist ultimately accepts because I will replace it with terms from P since they are the same properties. Just like I can't let you replace NP with whatever the dualist will ultimately accept about qualitative properties since you will fill it out in terms of Q!

Again, which of these ways of filling in the de re readings of P and Q is something that we will be able to determine in the future but are not able to do so now. So at present a priori methods are of no use. We must focus on doing the empirical investigation that will allow us to do the a priori work; but that is all the Type C physicalist has ever wanted...

you haven't understood my position.Well, this is a bit snarky, but I don't think anyone really understands your position since no one has the faintest idea what irreducible primitive qualitative properties are like. You want to say they are like seeing blue and feeling pain but those are physical properties for me! I just can't imagine what the kinds of things you are really talking about are like...

Finally, I'll just note that whatever you think about this debate over the zoombie argument you can't have any similar qualms about what I call the Shombie argument (starts from the premise (P & Q) is ideally conceivable). A shombie is my complete micro-physical duplicate that has qualitative properties in just the same way that I do...this is the typical thought experiment that the physicalist brings up. Used by Frankish, Piccinini, and Balog recently and it obviously meets your criteria for type-(ii) contestability, right?

Anyway, this is getting way too long! I'll leave off now and see what you have to say (if you want I can move this over to my blog since I know you don't like long comments...)

David Chalmer's argument is an argument that uses semantic premises to draw metaphysical conclusions about what is and is not "physical". The input is a sentence, a semantic object, not a metaphysical one. If the sentence is not a priori contradictory, then it specifies an epistemic scenario. And if the sentence has the further property of being semantically "neutral", in that it has identical primary and secondary intensions, then its resulting epistemic scenario can be mapped to a metaphysically possible world. Once we get to the possible world we can begin talking about what is and is not "physical".

Richard Brown's argument uses facts about what is and is not physical as the input of the argument, and is trying to derive the fact that... something is or is not physical. I guess you can kind of look at this as a problem of domains, the 2D semantic argument needs an input that is a semantically neutral sentence, but Richard is giving it a placeholder for a sentence while promising that whatever eventually fills the placeholder is "not physical". The end result is not a sentence at all, is not semantically neutral, and can not be the input of a 2D argument.

"I assume that you mean that we are to replace the placeholders with precise specifications of the properties in question."

Nope. The 'de re' stuff just means that we have to actually replace the placeholders with the precise sentences that they stand for. But we absolutely do NOT have to further replace those sentences with their ultimate truthmakers (since those are in dispute; such a requirement would make conceivability arguments strictly impossible to get off the ground).

So: replace 'P' with whatever physical facts you think obtain, and replace 'Q' with an uncontroversial phenomenal fact, e.g. "RC is having a conscious visual experience of blueness" (or whatever). We can disagree about the ultimate story why this is true, but we should all agree that the provided sentence is, indeed, a true qualia fact, and hence one that you are committed to thinking is entailed by [the replacement for P].

P.S. "the zombie argument, as it stands now, is only good for figuring out where your intuitions lie or correcting an implicit tension in one's "web of beliefs""

Um, that's the most that any argument can ever do. (Unless you think some arguments have magical persuasive powers that will change even the minds of people who reflectively disbelieve its premises.) That doesn't make it a bad argument, as you seem to think. (Of course, I've pointed out before that your meta-philosophical views incoherently imply that good argumentation is impossible.)

Your parody, by contrast, is question-begging in the strong sense that it wouldn't rationally persuade any opponent even by a degree.

[But if you wish to dispute these points, please do so in the appropriate linked threads, so as to keep this thread focused on clearing up the P-NP issue.]

I do disagree with your postscript, but will have to postpone disputing it for later...

Soulman: None of the sentences in Q have identical primary and secondary intensions (according to me and physicalists like me) which is why they are not semantically neutral which is why (P & ~Q) is contested which is why that argument is just as bad as mine...

RB,Well, even if you are right that qualia statements are not semantically neutral, Chalmers argument is still only half as bad as yours.

In the zombie argument P is a sentence that describes things about our world while remaining agnostic on whether they are physical or not, because we don't know what the word "physical" means. "Physical" should be anything that supervenes on some base facts that we can all agree on as being important. The point of the argument is to show that these base facts do not entail facts about qualia, and so qualia are not physical.

Your argument uses NP, which allegedly stands for a set of facts that we have no chance of agreeing on, and you expressly stipulate that they are not physical. By stipulating from the beginning that they aren't physical, you short circuit what the argument is supposed to demonstrate... Because we don't know what it means for something to be physical. This type of argument needs to rely on uncontroversial assumptions about what we mean when we use words, as in what we mean a priori, and if they are semantically neutral terms we can derive what we a posteriori and make metaphysical judgments about them. You have put the cart before the horse.

As for qualia terms not being semantically neutral, are you using this to inform your physicalist conclusions, or are you concluding this because you are a physicalist? I'd be interested to hear your arguments in the former case, although maybe it's off topic for this thread.

RB - "The problem arises here since I think that qualitative facts ARE physical facts..."

At this stage I am beginning to wonder if you are being intentionally uncooperative. When I ask you to "replace 'P' with whatever physical facts you think obtain", you have two options: you can explicitly include mention of qualia in this list or not.

If you think you cannot specify the base facts without explicitly mentioning qualia, then you are a "physicalist in name only". But that is not your view. You think we can (in principle) specify the base facts P without any explicit mention of qualia. And since this is your view, no problems arise just because you happen to think that the things you do specify will turn out to entail the existence of qualia.

You can give the specification P (that doesn't explicitly mention qualia) and dualists will accept it as uncontested. Then we can take an uncontested fact about qualia (as specified above) for Q, and together this means that we have an uncontested specification to flesh out the placeholder [P & ~Q].

RC: I am not trying to do anything intentionally except try to get you to see the point I am making. I have tried to more carefully spell out the point I am trying to make in this post: The Contestability of (P & ~Q)

Soulman: I agree that the zoombie argument is bad, but want to insist that it is bad in the same (but opposite) way that the zombie argument is bad. So I agree that the way I spell out NP in effect stipulates that qualitative properties are not non-physical properties and then posits that as ideally conceivable but, I argue, the zombie argument fails in the same (but opposite) way by stipulating that qualitative properties aren't physical properties. It does this in the way that the semantics for Q are spelled out. I want to do the semantics for Q in a way that it is either harmelss to say that (P & ~Q) is conceivable or (P & ~Q) isn't ideally conceivable at all. RC says that I am not allowed to do the semantics that way. So the two arguments are just as bad in just the right respects...but for the full story I'll refer you to the post linked to above.

Brown - I gather from your linked post that you are using the term 'contestable' differently from me. Again, I am simply concerned with the question whether physicalists and dualists can agree on a true sentence to fill in the relevant placeholders.

We can agree that there's a truth expressible in the language of physical science to replace 'P', and we can surely find an uncontroversial truth in the language of ordinary phenomenology to replace 'Q'. (We cannot, on the other hand, agree on what sentence to replace 'NP' with. So this brings out the vital disanalogy.)

Chappell: I agree that your point is very simple; too simple to be any good. Mine At this point I doubt that we are going to be able to see eye to eye on this issue, so let me just try to sum up the point I am making and then I'll let you have the final word.

You define two kinds of contestability:

(i) Contested initial specifications of what is to be conceived (e.g. what is to replace the placeholder ‘NP’)

(ii) An uncontested specification (e.g. ‘P and ~Q’) for which it’s contested whether it is ideally conceivable.Your complaint against the zoombie argument can then be stated as either NP is replaced by a list of non-physical properties that no dualist could ever agree to, in which case NP is type-(i) contested and is "no damn good" or NP is filled out with an incomplete list of non-physical properties, in which case it is conceivable that (NP & ~Q) but that is no threat to dualism.

I claim that this mirrors my complaint against the zombie argument and so the zoombie argument does what it is supposed to do. Why so? Well, either the statements in Q are read de re or not. If they are then Q will be type-(i) contested, where as if those statements are not read de re, as you insist that they should not be then (P & ~Q) is conceivable but it is no threat to physicalism because Q isn't all of the qualitative facts; there may well be other qualitative facts.

Consider an analogy. Let 'S' name all of the Superman facts and 'C' name all of the clark Kent facts. Is (C & ~S) conceivable? Well, of course it is if what one means is that there is a possible world where the descriptions in C and S pick out distinct individuals and the distinct individual picked out by S isn't there. But does that show that it is false that C=S? No, because given the purely descriptive statements in C and S you can't get from there to secondary conceivability. This is because the primary and seconday intensions of these statements differ.

The same is true for (P & ~Q). We can conceive of c-fiber firing without pain if we take 'c-fiber firing' and 'pain' to designate two different properties and the property picked out by 'pain' is not there but we then can't get from there to secondary conceivability The only way you can get to there is if you read 'pain' de re and substitute a distinct property which is not included in P for it, which of course, no physicalist like me would ever agree to! (NB: this is not to say that some physicalists might (i.e. Type-B physicalists) but it is a mistake on thier part to do so, and besides I am not trying to illustrate what all physicalists think is wrong with the zombie argument but what physicalists LIKE ME think is wrong with it). Chalmers notes this problem is section 3 of the 2-D argument paper which prompts him to assert that the primary intensions and secondary intensions of statements in Q are identical, which in effect licenses the de re reading of statements in Q.

So, if you don't read the statements in Q de re then you can get the conceivability claim off the ground but not in a way that threatens physicalism and if you do read them de re then the zombie argument is type-(i) contested Which is EXACTLY the problem you point out with the zoobie argument. Granted there is the disanalogy you point to, i.e. whether we read NP de re vs. whether we read the statements in Q de re, but that disanalogy is not vital for the purposes I want to employ it for.

"(P & ~Q) is conceivable but it is no threat to physicalism because Q isn't all of the qualitative facts; there may well be other qualitative facts."

Simply put, this reasoning get things backwards. Recall that the type-A physicalist is committed to thinking that the complete physical description P suffices to imply each qualitative truth Q. It doesn't matter whether there are other qualitative truths in addition. (If there are, then they are committed to P entailing those too; but it won't affect whether P implies Q. P alone is supposed to suffice for that.)

* * *

Let's recap. It is agreed by all that some ordinary phenomenal claim Q is true. Further, since none of us are type-B materialists who countenance 'strong necessities', we all agree that the base facts (whatever they are) imply all truths. So, in particular, the base facts imply Q.

We dispute what needs to be included in the base facts -- in particular, whether facts stateable in purely physical terms suffice. Since we are all committed to our specified base facts implying Q, one way to test these views is to question whether this implication indeed holds, or whether it is instead conceivable to have all the candidate base facts without Q. (If this were conceivable, it would show that the candidate base facts failed to exhaust the base facts. For example, if our candidate exhaustive specification were the physical facts P, then the conceivability of P & ~Q would establish that - contrary to physicalism - we need other base facts besides just P.)

So this is how zombie-style conceivability arguments work. Start by taking your opponents' allegedly exhausted base facts X, and show that X fails to imply some uncontroversial truth Q. It should be obvious that such arguments can hope to "get off the ground" only if your opponent doesn't explicitly include the target Q in their specification of the base facts. Otherwise (like the "physicalist in name only"), they will be transparently immune to such arguments -- which is why anyone who understands the logic of conceivability arguments could see right away that the zoombie parody never had a chance.

To be perfectly clear: each theorist is only committed to the incompatibility of ~Q with what they personally take to be a complete specification of the base facts. (We must think that the complete base facts entail Q, but there's clearly no problem in the failure of a mere subset to do so.) Hence, if your list 'NP' leaves out some of the dualist's candidate base facts (e.g. Q itself), then the dualist simply is not committed to your list NP entailing Q. That's why your proposed conceivability claim is no threat to the dualist.

Now, you want to claim that physicalists can raise a similar objection to the original zombie argument, but this is not so. To escape your commitment to P entailing Q, you must think that there are other base facts besides P (that is, you must become a "physicalist in name only", which you do not want to do). It is no help at all for you to think that there are other qualitative (on your view, derivative) truths besides Q.

What you don't seem to be getting is that if the primary intensions of statements in Q are not identical to their secondary intensions then there is no way to guarantee that the qualitative properties that are absent in your imagined world are our qualitative properties. And, of course, the failure of P to entail those other properties is no threat to physicalism...but if you assume that they are then you run into the type-(i) contestability issue. To get the zombie argument off the ground you have to get the physicalist to agree to treating the properties in P and the properties in Q as distinct properties, which is already to admit that physicalism is false. That is why the argument is no damn good.

"To get the zombie argument off the ground you have to get the physicalist to agree to treating the properties in P and the properties in Q as distinct properties, which is already to admit that physicalism is false."

This is not true at all. P and Q are [placeholders for] sentences, so we merely need to treat physical language/concepts as distinct from phenomenological language/concepts, which is surely uncontroversial, even to those who ultimately think there is a link between the two. (Compare: I think the microphysical facts suffice to settle the chair-and-table facts. Still, I admit that they invoke different concepts, so a conceivability argument could "get off the ground" in my most minimal sense -- though it would nonetheless soon fail because it's sufficiently clear that a world microphysically identical to ours but lacking tables is not, in fact, conceivable at all. But that's a substantive failure in the argument, rather than a problem in the legitimacy of its very set-up.)

"if the primary intensions of statements in Q are not identical to their secondary intensions then there is no way to guarantee that the qualitative properties that are absent in your imagined world are our qualitative properties"

Such problems are very easily avoided. As previously noted, any term with diverging intensions has a semantically neutral analogue which we can use in its place. (Intuitively: talk of "painful feelings" rather than "pain", etc.) So just swap out the rigid designators for their semantically neutral 'reference fixing descriptions', and we're fine. There's no denying that there are some semantically neutral phenomenal truths, so the physicalist can pick whichever they like for Q, so there's no scope for type-i contestability here.

To what extent does your argument depend on the existence of narrow content? While I strongly lead toward accepting the existence of narrow content, I'm curious if your argument can get by with less.

For what it's worth, I'm also very fond of the idea of strong necessities. I was about to object that epistemic possibility is wider than metaphysical possibility, but I see you've already given an argument from parsimony against such dualism about possibility. Given that you're arguing for a different kind of dualism, using this premise, I think we are at some kind of standoff here.

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